There are a few variations of the legends surrounding the origin of coffee, but the highlights remain the same: Some Ethiopian goats graze on red berries. The goats get a tad bouncy. Kaldi, the goatherd, notices the bouncy goats. Coffee’s effects are discovered.

A few centuries later, more than 50 percent of American adults drink an average of 3.1 cups a day, according to a study by the Harvard School of Public Health on the caffeinated beverage. A few of the larger coffee chains across this buzzing nation are using National Coffee Day on Sept. 29 to say “thank you” for such impressive consumer dedication.

Head to the nearest 7-Eleven to say, “You’re welcome.”

The company is offering free medium coffees (and lattes and cappuccinos) on Sept. 29 from 7-11 a.m. “Like” its Facebook page on Wednesday, Sept. 28, and have the added bonus of playing “Dip-a-Drip” for a chance to win a $25 gift card to the convenience store.

Happy bouncing!